The UK's first car-share motorway lane scheme is to be trialled on the M1, the Government announced yesterday.

The dedicated lane will operate at peak times for cars carrying two or more people between junction seven (St Albans, Hertfordshire) and junction ten (Luton, Bedfordshire), with an option to extend it to junction 13 at Milton Keynes, Buckingham-shire.

The lane will operate from 7am to 10am and 4pm to 7pm. It will be used as a normal lane outside these hours.

Announced yesterday by Transport Secretary Alistair Darling, it aims to encourage drivers to share cars.

Mr Darling said: "The Government is determined to tackle congestion - adding capacity where necessary and making better use of existing road space.

"Car pool lanes encourage drivers to share their vehicle by providing dedicated lanes for vehicles with passengers.

"Making better use of our road network, these lanes have been used to great effect both in America and Australia and could play a key role in reducing congestion on Britain's motorways.

"I hope motorists will be encouraged to consider car pooling and take advantage of the new lanes. It works elsewhere and there is no reason why it can't work here as well."

Work is already planned to widen the M1 at this point, from three lanes to four lanes in each direction.

It is estimated there would be five per cent fewer cars on the road if car sharing was adopted. Work is due to start next autumn.

More people would travel in car pool lanes and these travellers would expect their journey times to be reduced.

That improvement is expected to outweigh possible increases in journey times for people travelling on their own.

Car pool lanes have been successfully used in the US since the 1970s, and have been found to be effective on motorways of four lanes or more.